Q: My questions have to do with existing ungrounded circuits in older homes. My understanding is that you should always replace worn-out two-slot receptacles with new two-slot receptacles (although they’re not always easy to find). However, I’ve also been told that in some locales you can install a three-prong receptacle in an ungrounded circuit as long as you fill the ground slot with epoxy. This is presumably to prevent someone from using a grounded appliance on the ungrounded circuit. What’s the code requirement, and what about this epoxy business?
Q: Is it acceptable to use plastic piping for the pressure-relief discharge on a domestic water heater? The BOCA code in my area requires that the discharge piping be rated at or above the temperature of the system, but it’s not clear whether that refers to the temperature of the water in the tank or the temperature setting of the relief valve.